CSV ⇄ JSON Converter
Convert CSV to JSON and JSON back to CSV, both directions.
Paste CSV to get a JSON array of objects (the first row is the header), or paste a JSON array to get CSV. Handles quoted fields, commas and newlines correctly. Everything runs in your browser, so your data stays private.
—
Switch between CSV to JSON and JSON to CSV using the buttons above the input box, then paste your data in. CSV input needs a header row as its first line; JSON input should be an array of objects. The converted result appears instantly below, ready to copy with the button next to it.
Common mistakes
- Pasting CSV without a header row turns your first data row into field names, shifting every value out of place.
- Spreadsheets that export semicolon-separated values (common in some European locales) aren't auto-detected — this tool only splits on commas, so semicolons pass straight through as one column.
- Nested JSON objects or arrays in a field aren't split into extra columns — they're converted to a JSON string inside a single CSV cell.
Frequently asked questions
How are CSV headers handled?
The first CSV row becomes the object keys; when going back to CSV, the union of all keys forms the header.
Does my CSV need a header row?
Yes — the first row is always treated as column names. If your data has no header, add one before pasting, or your first record will be used as field names.
What happens to nested JSON when converting to CSV?
Nested objects and arrays aren't split into extra columns. Each one becomes a compact JSON string inside a single cell.
Does this handle commas inside quoted values correctly?
Yes. Fields wrapped in double quotes can contain commas, line breaks, and escaped quotes without breaking the parsing.
What delimiter does it expect?
A comma. CSV that uses semicolons or tabs, common in some regional spreadsheet exports, needs to be converted to commas first.
Privacy
All processing happens locally in your browser. Your data is never uploaded.